Abstract

Anonymising services have evolved from simple proxies to complex systems.
Numerous techniques have been developed to thwart and confuse attackers, thereby
improving the degree of anonymity. These techniques are often presented as
additional advantages of speci

c anonymising services. Comparisons of anonymity services exist, however, there
is a need for a more structured approach towards the understanding of the various
techniques employed by these services.

This paper takes a meta-level look at connection anonymity, how it has
evolved and how and why certain design choices are made. A conceptual
framework describing what we consider to be important connection anonymity
factors will be proposed. We consider design factors, fundamental connection
anonymity functions and objectives. The framework aims to provide for
a more structured and formal view of current anonymising strategies and
techniques. It should thereby set the stage for further advances in connection
anonymity.